linux/fs/ext3/bitmap.c
Akinobu Mita 10d470849a ext3: use memweight()
Convert ext3_count_free() to use memweight() instead of table lookup
based counting clear bits implementation.  This change only affects the
code segments enabled by EXT3FS_DEBUG.

Note that this memweight() call can't be replaced with a single
bitmap_weight() call, although the pointer to the memory area is aligned
to long-word boundary.  Because the size of the memory area may not be a
multiple of BITS_PER_LONG, then it returns wrong value on big-endian
architecture.

This also includes the following changes.

- Remove unnecessary map == NULL check in ext3_count_free() which
  always takes non-null pointer as the memory area.

- Fix printk format warning that only reveals with EXT3FS_DEBUG.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Acked-by: Jan Kara <jack@suse.cz>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-30 17:25:16 -07:00

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/*
* linux/fs/ext3/bitmap.c
*
* Copyright (C) 1992, 1993, 1994, 1995
* Remy Card (card@masi.ibp.fr)
* Laboratoire MASI - Institut Blaise Pascal
* Universite Pierre et Marie Curie (Paris VI)
*/
#include "ext3.h"
#ifdef EXT3FS_DEBUG
unsigned long ext3_count_free (struct buffer_head * map, unsigned int numchars)
{
return numchars * BITS_PER_BYTE - memweight(map->b_data, numchars);
}
#endif /* EXT3FS_DEBUG */